IEEE C37.93 - GUIDE FOR POWER SYSTEM PROTECTIVE RELAY APPLICATIONS OF AUDIO TONES OVER VOICE GRADE CHANNELS Organization: IEEEDate: 2004-03-25Description:
Purpose
The primary purpose of this document is to guide the power
system user in applying, installing, and operating audio-tone
protective relaying systems over voice grade channels. Secondly, it
is to provide a reference for equipment manufacturers engaged in
the design and application of relaying equipment and for telephone
personnel engaged in providing telecommunications channels for
audio-tone protective relay schemes.